1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel having a trench discharge cell and a method of fabricating the same. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for improving luminescent efficiency and reducing driving voltage in plasma display panels.
2. Discussion of the Related Art
Plasma display panels (PDP's) are comprised of a large number of plasma cells that generate ultraviolet light. The UV light is then converted into visible display emission by a phosphor layer. The brightness and efficiency of the display are mainly dependent on the intensity and efficiency of the production of the UV light by the plasma cell.
A conventional structure of an AC type plasma display panel shown in FIG. 1. The conventional AC type plasma display panel is formed of a front substrate and a rear substrate. A space formed between the two substrates is filled with an inert gas.
The front substrate includes a first glass substrate 11, a transparent conductive layer 12 having a striped shape deposited thereon, and a bus electrode 13 generally formed of a silver paste and compensating a high resistance of a transparent dielectric layer 14. The transparent dielectric layer 14 limits the amount of current and transmits visible light discharge from a phosphor layer. A black stripe layer 15 is formed of a black insulating layer, which improves a contrast ratio. A protective layer (not shown) is formed of a magnesium oxide thin film, which is highly durable to the impact during ionic discharge and enhances discharge of the secondary electrons. A pair of electrodes, which are formed of the transparent conductive layer 12 and the bus electrode 13, is formed into one discharge cell.
The rear substrate includes a second glass substrate 16 having an address electrode 17 formed thereon, and a protective layer 18 for the address electrode, a barrier rib 19, and a phosphor layer 20 deposited thereon.
The operation of the plasma display panel having the above structure will now be described. A strong discharge occurs between the address electrodes 17 on the rear substrate and one of the electrode pairs on the front substrate. Then, an AC signal is sent to one of the electrode pairs on the front substrate in order to maintain plasma discharge. As a result of the discharge, photons with wavelengths in the ultra-violet region are emitted. The emission of the photons in the Ultra-violet region stimulates the phosphor layer 20 of the rear substrate, which emits visible light that is used to form the picture or image on the display.
In the plasma display device having the above-described structure, luminance and efficiency are the main factors that determine the quality of the device. The conventional AC type surface discharge PDP has the following disadvantages.
Due to the difference in length of the discharge paths inside the discharge cell and outside the discharge cell, the electric field cannot be uniformly generated. Therefore, a uniform discharge, whereby discharge is stronger in the inner portion of the unit discharge cell and becomes weaker as it nears the outer portion of the cell, and high luminescent efficiency resulting from the uniform discharge cannot be achieved. Furthermore, the electrodes have a structure of a two-dimensional flat surface. Thus, in accordance with a high resolution, the area of the electrode becomes smaller, the luminescent efficiency decreases, and the driving voltage increases.